Method of preparing valuable hydrocarbon products from acid sludge



Patented Apr. 7, 1936 UNITED STATES- PATENT OFFICE:

METHOD OF PREPARING VALUABLE HY- DROCARBON PRODUCT FROM ACID SLUDGE 1 Frederick W. Sullivan, Jr flammond, Ind., as-

signor' to Standard Oil Company (Indiana), Chicago, 111., a corporation of Indiana No Drawing. Application May30, 1930,

Serial No. 457,672

3 Claims. ,(o1.196-14s) This invention relates to a method of refining under whichPennsylvania oils have a coefiicient petroleum hydrocarbons and it pertains particof 100). lilarly to the production of high viscosity oil and he hydrogenation of acid sludge residue. NPA color Many petroleum oils (mixed base oils) contain 1 t 2? %1 ggl c l lg g gfb visttiify llx asphaltic, naphthenic, and/or unsaturated compounds which may be hydrogenated to increase their value. However, high viscosity lubricating $1 2 2 +3% oils cannot be satisfactorily produced by hydro- 82 genation because heavy oils tend to crack at hydrogenation temperatures. The object of my in- A great improvement in the final quality with vention is to obtain high viscosity oils from peheavy acid treatment will be noted, but due to troleum and at the same time to hydrogenate at excessive sludge loss such treatment has not preleastaportion of the asphaltic,naphthenic and/or viously been economically feasible. The present unsaturated hydrocarbons. process, by the recovery of valuable products from A further object is to provide a simple process the sludge, makes such heavy acid treatment posfor removing sulfur, sulfuric acid and related comsible. pounds, such as sulfonic acids, sulfuric esters, etc. The oil layer from the above treatment is finwhereby the sludge may be hydrogenated with a ished in the conventional manner; mahogany minimum amount of hydrogen and without inacids are extracted, and the oil is separated from jury to the catalyst. wax and preferably contacted with adsorbent clay In my process I treat a mixed base petroleum at high temperatures to yield a high viscosity luwith sulfuric acid and I separate the resulting bricating oil. oil layer from the acid sludge. I finish the oil The sludge from the above treatment is heated from the oil layer and obtain therefrom a high in an open vessel, pipe still, and/or any other 35 viscosity lubricating oil. I heat the acid sludge means to a temperature of about 400 or 500 F. to remove the water, sulfur, sulfuric acid and This heat treatment decomposes sulfonic acid, sulfuric acid compounds, the sulfur being removed sulfuric acid and sulfuric esters. The sulfur is in oxidized form. Finally, I hydrogenate the visremoved in the form of sulfur dioxide, and the cous material which has been produced from the water is removed as steam. The resulting prodacid sludge. The invention will be more clearly net is a viscous substance of complex molecular understood from the following description of a structure. By hydrogenatingthis substance I preferred embodiment. may obtain lubricating oils of relatively high vis- A lVlid-Continent crude oil may be heated in cosity together with lighter oil products. a conventional pipe still and fractionated in 2.0- The hydrogenation may be carried out in any cordance with conventional practice, and/ or it conventional apparatus by the use of any convenmay be reduced with steam so that cracking is tional catalyst. It should be noted that the comprevented. The residue, which may be replete removal of sulfur and sulfuric acid by heat duced crude, is then treated with strong sulfuric treatment prevents the sulfuric acid or acid comacid. This treatment comprises agitating the oil pounds from injuring the catalyst in the hydro- 40 with acid (about 93%), using about one-half genation step and it should also be noted that I pound of acid per gallon of reduced crude. The remove a large amount of sulfur in oxide form oil is then allowed to settle, the sludge is withwhich would otherwise require hydrogen for condrawn, and the oil is given another treatment, verting it into hydrogen-sulfide. By removing the number of treatments or dumps of acid sulfur in oxidized formI effect a marked economy used depending upon the nature of the reduced in the consumption of hydrogen. 7 crude and the desired characteristics of the fin- Wherever herein reference is made to the use ished oil. of some given amount of 100% acid, it is un- The effect of such successive treatments on the derstood to be not specifically limited to the use properties of the final lubricant made from a low of acid of that particular concentration, but to grade lubricating stock is shown in the following refer to the use of an amount of acid of some table. (This refers to a stock corresponding apconvenient concentration equivalent in amount proximately with S. A. E. grade 20. The figures to the stated amount of 100% sulfuric acid. given under Temperature Viscosity Index are Iclaim: the viscosity index according to Dean and Davis, 1. The method of preparing valuable hydrocarbon products from acid sludges formed in the treatment of petroleum with sulphuric acid, which comprises heating the sludge to a temperature between 400 and 500 F. whereby sulphur and sulphuric acid compounds are largely removed from the sludge without substantial formation of coke, and then subjecting the heated sludge to treatment with hydrogen in the presence of catalytic,

materials to produce viscous lubricating oil and lighter oil products therefrom.

2. The method of obtaining large yields of valuable lubricating oil from mixed base petroleums which comprises treating the petroleum with about one-half pound of concentrated sulfuric acid per gallon of petroleum whereby an oil layer and sludge are produced, recovering the oil layer from the sludge, heating the sludge to'a temperature between 400 F. and 500 F. whereby sulfur and sulfuric acid compounds are removed therefrom without substantial formation of coke, and then subjecting the heated sludge to treatment with hydrogen in the presence of catalytic materials to hydrogenate asphaltic, naphthenic and unsatarately withdrawing and recovering the oil layers after each treatment and finishing them to a high quality lubricating oil, heating the sludge to a temperature between 400 F. and 500 F. whereby sulfur and sulfuric acid compounds are removed therefrom as oxygen compounds of sulfur without substantial formation of coke, then subjecting the heated sludge to treatment with hydrogen in the presence of catalytic materials to produce a hydrogenated viscous lubricating oil and blending the oil initially separated from the sludge with the hydrogenated oil;

FREDERICK W. SULLIVAN, JR. 

